The AVCHD folder has to be in the root.
I'm generating AVCHD (2.0) structure from PowerDirector 11 and 12, I do mostly 3D using mt2s files from Sony HDR-TD10 camera.
What would be nice is to have all 3D movies from PowerDirector or copies you want from elsewhere on an external USB HDD and it works BUT you have to rename the root folder above BDMV to AVCHD of the movie you want to see... so plug the usb hdd to a laptop, change the folder name and reconnect to the Sony usb player...
What is weird from my point of view is why m2ts avchd 3D files when selecting from the usb drive by the player will only play in 2D?? The file is from the HDR-TD10 directly, why generating a AVCHD/BDMV directory so necessary... ?
Another comment, I also have a Sony XBR-65HX929. Weird, the USB port does not support NTFS structure (the S580 does) and won't play my 3D AVCHD/BDMV... One thing it was over the S580, is the YouTube apps, does play YouTube 3D vidoes and you can change the quality ot HD in the app.
Check my YouTube channel from within the YouTube app VE2FET. Or, this is a list of my YouTube 3D videos made with HDR-TD10 (not 60fps on youtube! :-)
I'm interested in what you guys came up to so far?